Electronic messaging has become a vital part of business and everyday life. The ease and efficiency of sending electronic messages, such as email messages, has led to a steady increase in the number of messages that many people receive every day. As a result, users must spend more time sifting through and reading received messages. For some people, particularly those in leadership positions, the volume of electronic messages received daily renders it nearly impossible to review each message. For example, a chief executive officer of a large corporation might receive more than 500 messages per day. Typically, electronic messages range from the important to the mundane, such as unsolicited advertisements and spam. Thus, users must exercise care while scanning received electronic messages to ensure that important messages are not overlooked. However, scanning through more than 500 messages is a daunting and time consuming task.